I don't like the idea of moving from google's ecosystem to proton. While they're better, ecosystems tend to get locked down or change for the worse.I'm not planning to repeat the google cycle. I got my own domain for email, bitwarden for passwords, firefox forks for browsing, and many other stuff to get off google. Also I realised that stuff like contacts, notes, calendar don't really need to be on the cloud, but I'm planning to self host some services like that, mostly for the nerd in me.

Well WebDav/CalDav/CardDav works quite OK. Baïkal is trivial to selfhost (cal+card) then you just pick some webdav implementation like KaraDav/PicoDav/FlyDav and you are good.

Email is really the one that requires lot of caring about so not easy to self host.